Install a Nessus Agent on Linux

Caution: If you install a Nessus Agent, Manager, or Scanner on a system with an existing Nessus Agent, Manager, or Scanner running nessusd, the installation process will kill all other nessusd processes. You may lose scan data as a result.

Retrieve Agent Linking Key from within Nessus

Log in to Nessus.

Select the button.

On the Scanners / Agents / Linked page, select Agent > Linked and read the on-screen message. Agents can be linked to this manager using the provided key with the following setup instructions. Once linked, they must be added to a group for use when configuring scans.

Also, linked agents will automatically download plugins from the manager upon connection. Please note, this process can take several minutes and is required before an agent will return scan results.

Select the setup instructions link.

The Agent Setup Instructions window appears.

Record the host, port, and key values. These values will be used during the installation of the Nessus Agent.

Note: If you attempt to clone an Agent and link it to Nessus Manager, a 409 error may appear. This is because another machine has been linked with the same uuid value in the /etc/machine_id or /etc/tenable_tag file. To resolve this issue, replace the value in the /etc/tenable_tag file with a valid UUIDv4 value. If the /etc/machine_id file does not exist, you can delete /etc/tenable_tag to generate a new value.

Verify Linked Agent.

In Nessus, select the button.

View Agents on the Scanners / Agents / Linked page.

Note: If information provided in your command string is incorrect, a Failed to link agent error will be displayed.